Self-contained burglar alarm unit



Nov. 17, 1953 E. DAVIS 2,659,333

SELF-CONTAINED BURGLAR ALARM UNIT Filed Sept. 18, 1951 2 Sheets-Sheet 1v IN VEN TOR.

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ATTU R N EYB' Nov. 17, 1953 L. E. DAVIS 2,659,333

SELF-CONTAINED BURGLAR ALARM UNIT Filed Sept. 18, 1951 2 Sheets-Sheet 2I N VEN TOR.

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ATTCI RN EYS Patented Nov. 17, 1953 UNITED STATES PATENT OFFICESELF-CONTAINED BURGLAR ALARM UNIT Lewis E. Davis, Burbank, Calif.

Application September 18, 1951, Serial No. 247,086

This invention relates to individual burglar alarm units of the clockmechanism actuated type in which the parts are actuated by springsinstead of electricity, and in'particular a casing having a coverproviding a bell with a spring arm having a rubber cup on the extendedend piv otally mounted in the casing and positioned to release a bellclapper when an object suchas a window, is moved in either direction inrelation to the side of a window frame upon which the casing is mounted.

The purpose of this invention is to provide a comparatively smallburglar alarm unit wherein an individual may attach a unit to differentobiects in the home such as doors, windows, and the like and wherein oneunit is installed on each of said objects and the units areindependently actuated.

Various types of independently operating burglar alarm units have beenprovided for windows, doors, the like, however, for the averagehousehold use where elaborate units are not required it is desirable toprovide a small independently operated unit wherein only one, or as manyunits as may be desired may be used in a residence.

The object of this invention is, therefore, to provide means for forminga burglar alarm unit whereby a single unit may be used on each window,door, or the like of a residence and-wherein only one unit, or as manyunits as may be desired may be used.

Another object of the invention is to provide an individual burglaralarm unit that operates independent of electrical connections.

Another object of the invention is to provide a burglar alarm unit inWhich the alarm is sounded at the unit whereby both the intruder and theoccupant of the residence or building know that an alarm beensounded.

A further object of the invention is to provide an individual alarm unitwhich is of a simple and economical construction.

With these and other objects and advantages in view the inventionembodies a mounting plate having clock works mounted thereon, with anoperating arm extended therefrom and with a bell positioned over theclock works and adapted to be engaged by a clapper thereof.

Qther features and advantages of the invention will appear from thefollowing description taken,

in connection with the drawings wherein:

Figure l is a sectional plan through the individual burglar alarm unittaken on line l-l of Figure 2.

1 Claim. (Cl. 116-91) Figure 2 is a front elevational view of the unitwith the cover or bell broken away and shown in section.

Figure 3 is an end elevational view of the unit looking toward the endfrom which the vacuum cup carrying spring arm extends.

Figure 4 is a sectional plan through the unit taken on line 4- of Figure2.

Figure 5 is a longitudinal section through the unit taken on line 5-5 ofFigure 1.

Figure 6 is a detail taken on line 66 of Fig ure 1 illustrating themounting of the spring arm and showing a pin which provides a triggerfor holding and releasing the bell clapper of the unit.

Figure '2 is a sectionsimilar to that shown in Figure 6 being taken online T-l of Figure 1.

Referring now to the drawings wherein like reference characters denotecorresponding parts theindividual burglar alarm unit of this inventionincludes a mounting plate Ill, L-shape in cross section upon whichconventional clock works are mounted, a support plate H carried by themounting plate, a cover [2 providing a bell, and a springarm l3 having arubber cup hi on the outer end and pivotally mounted on a post I5. I

The mounting plate It is provided with a flange iii in which screw holesI? are provided by which the unit is attached to a window or door frame,as indicated by the numeral It? with screws i9. 7

I The support plate I l is spaced from the mounting plate It by aplurality of posts 20, 2! and 22 and the posts, which are provided withthreaded socketsin the ends, are secured to the mounting plate It byscrews 23 and to the support plate I I by screws 26.

Elie clock works, which is positioned between the plates 19 and. Elincludes a main spring 25, and a gear 26' having a pawl 2! pivotallymounted thereon and held into engagement with a ratchet wheel 23 by aspring 29. The spring is mounted on a winding stem 33 having a key illon the outer end and the gear 26 meshes with a pinion 32 on a shaft 33on which a toothed wheel 34 is mounted. The toothed wheel is positionedto be engaged by projections of an escapement arm 35 that is pivotallymounted on a pin 36 and that is positioned to be held stationary by apin or trigger 31. I

The eseapement arm 35, which provides a bell clapper, is mounted wherebya knob 38 on one end engages the cover or bell I2 as the escapement armis operated by the toothed wheel 34 upon release of the escapement armby the pin 31. The ends of the pins 33 and 3B are joumaled in themounting and supporting plates l and II respectively.

The cover or bell I2 is supported from the support plate H by a post 39,the lower end of the post being secured in the support plate and theupper end provided with a threaded socket 40 into which a screw 4| thatholds the bell to the post, is threaded.

The spring arm 13 is adjustably mounted in a socket 42 in which it isheld by a set screw 43 and the socket is provided with an extended stem44 which is ivotally mounted by a threaded stud 45 on the upper end ofthe post l5. The stud is provided with a nut 46 and a spring 41positioned on the stud is provided with an extended end 48 that urgesthe spring arm l3 downwardly with the rubber cup M in engagement withthe upper surface of a top rail of a window sash as indicated by thenumeral 49.

The socket '44 is also provided with a point 50 that rides on the uppersurface of a spring plate or arm that carries the pin or trigger 31, andthe arm 55 is mounted under the head of the screw 24 that is threaded inthe socket in the upper end of the post 22. The end of the arm 5| isprovided with an opening 52, as shown in Figure 7, that is positionedaround the post l5, and which is formed in a bent or inclined section 53on the outer end of the arm.

The post I5 is mounted in the support plate II as illustrated in Figure6 whereby a mounting flange 54 is resiliently held against one side ofthe plate H by a spring washer 55 that is secured by a nut 56 on a stud51 which extends from the flange 54, the stud passing through the plateH.

The section 53 is circular in shape, as shown in Figure 1, whereby thepoint or projection 50 may travel in a complete circle and still be inengagement with the upper surface of thev arm.

With the parts in the cocked position, as illustrated in Figures 2, 6and 7 the trigger or pin 31 is in engagement with the bell clapper baseor escapement arm 35 and should the window sash be raised or a dooropened the arm l3 would spring upward or outward, dependin upon themanner in which the device is installed, and in this movement the point50 moves away from the arm 5| and the resiliency of the arm withdrawsthe pin 31 thereby releasing the arm 35. Upon release of the arm 35 thebell clapper will operate to ring the bell.

Should it be desired to disengage the alarm it is only necessary to movethe arm [3 through an angle of 90 degrees whereby the arm 5| will beheld downwardly with the pin 31 in engagement with the bell clapperbase.

The spring wire or arm l3 extends through a 6 slot til in one end of thecover or bell l2, as

4 shown in Figures 1 and 3, whereby the wire arm is free to moveupwardly or downwardly with the movement of the sash or door.

with the parts arranged in this manner a home guard alarm device orindividual burglar alarm is provided and the device may readily beinstalled upon windows, doors, or other objects where protection isdesired and should an intruder attempt to open a window or door or movean object the bell clapper would be released and an alarm sounded at thepoint where the burglary is attempted. The alarm device therefore, warnsoccupants of the household and discourages the intruder.

It will be understood that modifications may be made in the design andarrangement of the parts without departin ro the sp f the invention.

What is claimed is:

In a burglar alarm, an L-shaped mounting plate provided with a flangefor attachment to a supporting structure, a support plate carried bysaid mounting plate, a cover providing a bell and having a slot therein,a spring-arm pivotally extending through said slot, a resilient cupconnected to the outer end of said spring-arm, a plurality of spacedparallel posts extending between said mounting plate and support plateand secured thereto, a clock-work positioned between said pair of platesand including a main spring, a winding stem having its inner endconnected to said main spring, a gear mounted on said stem. a rachetwheel arranged contiguous to said gear, a spring pressed pivotallymounted pawl arranged in engagement with said rachet wheel, a shaftspaced from said stem, a pinion mounted on said shaft and meshing withsaid gear, a tooth wheel positioned within said cover, a pivotallymounted escapement arm having a knob on one end providing a bell clapperfor engagement with said cover, said escapement arm having projectionsfor engagement with said tooth wheel, a trigger for controlling movementof said escapement arm. a post extending between said support plate andcover. and secured thereto, a spring member for biasing said spring armin one direction, a socket connected to the inner end of said springarm. and having a point extending therefrom, and a spring plateextending from said trigger and having a circular section engaged bysaid point.

LEWIS E. DAVIS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 773,165 Smith Oct. 25, 1904 2,469,528 suma May 10, 19492,611,334 Counts et a1 Sept. 23, 1952

